<?php 

function sum($a=0, $b=0)
{
  return ($a+$b);
}

function sub($a=0, $b=0)
{
  return ($a-$b);
}

function multiply($a=1, $b=1)
{
  return ($a*$b);
}

function divide($a=1, $b=1)
{
  return ($a/$b);
}

$fun = 'divide';

$functions = array('sum','multiply','divide','sub');

shuffle($functions);

echo "The ".$functions[0]." is ".$functions[0](50,5);




